noncliff: add copy, == for GeneralizedStabilizer, UnitaryPauliChannel (…

…#419)

src/nonclifford.jl

@@ -64,6 +64,8 @@ function GeneralizedStabilizer(state)
 end
 
 GeneralizedStabilizer(s::GeneralizedStabilizer) = s
+Base.copy(sm::GeneralizedStabilizer) = GeneralizedStabilizer(copy(sm.stab),copy(sm.destabweights))
+Base.:(==)(sm₁::GeneralizedStabilizer, sm₂::GeneralizedStabilizer) = sm₁.stab==sm₂.stab && sm₁.destabweights==sm₂.destabweights
 
 function Base.show(io::IO, s::GeneralizedStabilizer)
     println(io, "A mixture ∑ ϕᵢⱼ Pᵢ ρ Pⱼ† where ρ is")
@@ -145,8 +147,11 @@ with ϕᵢⱼ | Pᵢ | Pⱼ:
  0.853553+0.0im | + _ | + _
  0.146447+0.0im | + Z | + Z
 
-julia> expect(P"-X", sm)
+julia> χ′ = expect(P"-X", sm)
 0.7071067811865475 + 0.0im
+
+julia> prob = (real(χ′)+1)/2
+0.8535533905932737
 ```
 
 """
@@ -342,6 +347,8 @@ struct UnitaryPauliChannel{T,S,P} <: AbstractPauliChannel
 end
 
 PauliChannel(p::UnitaryPauliChannel) = p.paulichannel
+Base.copy(p::UnitaryPauliChannel) = UnitaryPauliChannel(map(copy, p.paulis), map(copy, p.weights))
+Base.:(==)(p₁::UnitaryPauliChannel, p₂::UnitaryPauliChannel) = p₁.paulis==p₂.paulis && p₁.weights==p₂.weights
 
 function Base.show(io::IO, pc::UnitaryPauliChannel)
     println(io, "A unitary Pauli channel P = ∑ ϕᵢ Pᵢ with the following branches:")

test/test_nonclifford_quantumoptics.jl

@@ -50,3 +50,16 @@ qo_tgate.data[2,2] = exp(im*pi/4)
         end
     end
 end
+
+@testset "copy and ==" begin
+    for n in 1:10
+        s = random_stabilizer(n)
+        sm = GeneralizedStabilizer(s)
+        i = rand(1:n)
+        apply!(sm, embed(n, i, pcT))
+        smcopy = copy(sm)
+        @test smcopy == sm
+        nc = embed(n, rand(1:n), pcT)
+        @test copy(nc) == nc
+    end
+end